mthread and multiple header files

Question

I'm using mthreads (https://github.com/jlamothe/mthread) for my arduino. But now as the project is getting bigger, it would make sense to break it up in several files.

I successfully outsourced already a part which is not threaded. But somehow I cannot make up my mind how to use mthread in conjunction with several header files.

here is what I got:

main: call header:

#include "tcan.h"

tcan.h:

#ifndef tcan_h
#define tcan_h
#include "Arduino.h"
class tcan : public Thread {
 public: tcan();
 protected: bool loop();
 private:
};
#endif

tcan.cpp

#include "Arduino.h"
#include "tcan.h"
#include <mcp_can.h>
bool tcan::loop() {
 // lala
 return true;
}

but I get an error when compiling:

tcan.h:6:28: error: expected class-name before '{' token class tcan : public Thread {

Thanks in advance

• user3704293: Check for circular #includes... The error can be caused by including Arduino.h twice.

Answer 1

The compiler error is due to that the compiler does not know what Thread is.

tcan.h:6:28: error: expected class-name before '{' token class tcan : public Thread {

The issue is that the header file is not complete. A good practice is to include all header files that are needed to read the header file. As Thread is defined in mthread.h the tcan.h file should be:

#ifndef tcan_h
#define tcan_h
#include <mthread.h>
class tcan : public Thread {
public: tcan();
protected: bool loop();
private:
};
#endif

Cheers!

• jblaze: that was the right hint "Assuming that Thread is defined in mcp_can.h". Of course I need to include "<mthread.h>". Thanks for the hint! It's working now.
• Mikael Patel: Great! I will update the answer with the correct include.